Lubricating oil



aws

Patented Dec. 6, 1938 LUBRICATING OE Bernard H. Shoemaker, Hammond, Ind., assignor to Standard Oil Company, Chicago, Ill., a corporation of Indiana No Drawing. Application November 16, 1936 Serial No. 111,085

16 Claims. (Cl. 879) This invention relatestolubricants and, in parthiocyanate. The reaction involved probably is ticular, to addition agents imparting to lubrias shown by the following equation cants improved properties. RCHO+R'SH+HC1 (dry) C.RCHSR'+HOH My invention has particular utility in preventcl ing and/or inhibiting the corrosion of hard I I 5 metal alloy bearings such as copper-lead, cad- RCH SR+NQSCN'M.RCH SR +Nacl mium-nickel, and cadmium-silver bearings which, 1 S UN to a large extent, have replaced soft metal bear- Examples of the compounds contemplated ings such as Babbitt metal in the trend toward within the scope of my invention are as follows:

internal combustion engines having high com- Ethyl alpha isothiocyano ethyl ether 10 pression ratios and having increased acceleration Ethyl alpha thiocyano ethyl thio ether and increased speed characteristics. The use of Butyl alpha thiocyano ethyl thio ether the hard metal bearings has created lubrication Butyl alpha thiocyano ethyl ether and corrosion problems, particularly in connec- Amyl alpha thiocyano butyl ether tion with highly refined oils, some of which may Amyl alpha isothiocyano butyl thio ether 15 be very corrosive to the hard metal bearings. Butyl alpha isothiocyano amyl other By (highly refined lubricating oils I mean My invention also contemplates the use of alviscous oils which have a minimum viscosity cohol and thiocyanic acid addition products such in the range of S. A. E. 10 oils and which have as the addition product of amyl alcohol and thio been subjected to such refining processes such cyanic acid having the formula HSCN-3C5H11OH. 20 as, for example, solvent extraction, that the par- Since these compounds are subjected to high aflinicity of the oil is markedly increased. It temperature conditions it is highly desirable that has been found that highly refined lubricating the compounds of the aforementioned type havoils cause corrosion to alloy bearings of the cading boiling points of about 400 F. or greater be mium-silver type to the extent of 5 mg/cm and used. 25

even greater when such bearings are submerged The efiectiveness of these compounds as corrofor 25 hours or less in an air-agitated oil which sion inhibitors is demonstrated by the following has been preoxidized at about 340 F. for 25 to 50 tests which were conducted under conditionsmore hours. The motor oils may be highly refined severe than those encountered in the actual oplubricating oils as such or mixtures of highly reeration of internal combustion engines. In the 30 fined lubricating oils with less highly'refined first test the weighed bearings are placed in a lubricating oils, or stated in another way, mixhighly refined oil containing the inhibitor and tures of corrosive oils and non-corrosive oils, the oil air agitated at about 341 F. At periodic examples of the latter being lubricating oil fracintervals the bearings are removed from the oil tions from Winkler crude or crudes of the Winkbath, washed free of oil and the loss in weight 35 ler type. determined.

I have found that corrosion of hard metal alloy Each time before being replaced in the oil bearings can be inhibited and highly desirable bath the bearings are polished bright and reproperties 6 be pa ted to t ubrica ing Oil weighed and again tested for predetermined pe- 40 by addin ther o p to 5% but preferably 0.05% riods. The results obtained in this test are tabu- 40 to 1% of certain thiocyano ethers, particularly lated below.

the alpha thiocyano ethers having the general Table] formula H Loss in mg/cmJ- R -,IJ X R' periods 45 1st 2nd 3rd in which R and R are alkyl or aralkyl radicals, Y is a thiocyano radical or an isothiocyano radical and X is either an oxygen or sulfur group. 50

These compounds may be economically preher 0.1 0.0 0.0 pared by reacting an aldehyde with mercaptan ititdfz.fi'fiiffftifflff?.RTYYK 0.1 1.1 at or an alcohol in the presence of dry hydrochloric Control+.2% amyl isothiocya u y acid and Subsequently reacting the resulting cfifitfiiiaiis'c'ii i'tmi'itttaijiiI: 312 3:3 333 product with a metal thiocyanate such as sodium 55 Control Control+.2% amyl thiocyano methyl In the other test the oil containing .2% of amyl alpha thiocyano butyl ether was tested in a sixcylinder internal combustion engine having cadmium-silver bearings and copper-lead bearings and operated at about 2500 R. P. M. with an oil temperature of about 320 F. and a jacket temperature of about 250 F. The results of this test are tabulated below.

In addition to inhibiting the corrosion of hard metal alloy bearings compounds of the foregoing type when used in quantities up to 10 to 15% improve the film strength of the lubricant to which they are added and also impart to such lubricants improved extreme pressure characteristics. These compounds may also be used to improve the lubricity and other properties of lubricating oils.

Some of the hereinbefore named compounds may not be completely soluble in the lubricant, in which case efi'ective results are obtained by suspending the inhibitor in the lubricant by means of asmall amount of a peptizing agent suchas aluminum naphthenate, aluminum stearate, etc.

While I have described my invention with certain specific embodiments thereof I do not wish to be limited thereby except as defined by the appended claims which should be given the broadest interpretation permitted by the prior art.

I claim:

1. An improved lubricant comprising a mineral lubricating oil and from about 0.05% to about 15% of an ether having the general formula in which R and R are alkyl radicals, Y is a radical selected from the group consisting of a thiocyano radical and an isothiocyano radical and X is an element selected from the group consisting of oxygen and sulfur.

2. An improved lubricant comprising a mineral lubricating oil and from about 0.05% to about 15% of an alkyl thiocyano ether having the general formula about 15% of an alkyl isothiocyano ether having the general formula H R Jo R' 1 10s in which R and R are alkyl radicals.

4. An improved lubricant comprising a mineral lubricating oil and from about 0.05% to about 15% of an alkyl alpha thiocyano ether having the general formula in which R and R. are alkyl radicals.

5. An improved lubricant comprising a mineral lubricating oil and from about 0.05% to about 15% of an alkyl alpha isothiocyano ether having the general formula in which R and R are alkyl radicals.

6. An improved lubricant comprising a mineral lubricating oil and from about 0.05% to about 15% of a butyl alpha isothiocyano amyl ether.

7. A corrosion inhibited lubricating oil comprising a mineral lubricating oil and 0.05 to 1% of an alkyl thiocyano ether having the general formula in which R and R are alkyl radicals, Y is a radical selected from the group consisting of a thiocyano radical and an iso thiocyano radical and X is an element selected from the group consisting of oxygen and sulfur.

8. A corrosion inhibited lubricating oil comprising a mineral lubricating oil and from about 0.05% to 5% of an alkyl thiocyano ether having the general formula H R-l-O-R say in which R and R are alkyl radicals.

9. A corrosion inhibited lubricating oil comprising a mineral lubricating oil and from about 0.05% to about 5% of an alkyl isothiocyano ether having the general formula in which R and R are alkyl radicals.

10. A corrosion inhibited lubricating oil comprising a mineral lubricating oil and from about 0 .05% to about 5% of an alkyl alpha thiocyano ether having the general formula in which R and R are alkyl radicals.

11. A corrosion inhibited lubricating oil comprising a mineral lubricating oil and from about 0.05% to about 5% of an alkyl alpha isothiocyano ether having the general formula i RCOR' NCS in which R and R are alkyl radicals.

12. A corrosion inhibited lubricating oil comprising a mineral lubricating oil and from about 0.05% to about 5% of a butyl alpha isothiocyano amyl ether.

13. The method of preventing corrosion of bearing metal alloys selected from the group consisting of cadmium-silver alloys, cadmium-nickel alloys, and copper-lead alloys, in the presence of highly refined lubricating oils in internal combustion engines which comprises adding to said lubricating oils from about 0.05% to about 5% of an ether having the general formula in which R. and R. are alkyl radicals, Y is a radical selected from the group consisting of a thiocyano radical and an isothiocyano radical and X is an element selected from the group consisting of oxygen and sulfur.

14. The method of preventing corrosion t bearing metal alloys selected from the group consisting of cadmium-silver alloys, cadmiumnickel alloys and copper-lead alloys in the presence of highly refined lubricating oils in internal combustion engines which comprises adding to said lubricating oils from about 0.05% to about of an amyl-isothiocyano butyl-thioether.

15. A corrosion inhibited lubricating oil comprising a mineral lubricating oil and from about 0.05% to 5% of a thio ether having the general formula in which R and R are alkyl radicals and Y is a radical selected from the group consisting of thiocyano radicals and isothiocyano radicals.

BERNARD H. SHOEMAICER. 

